Spark-plug.



w. H. SIPPEL.

SPARK PLUG.

APPLICATION FILED MAY 6, \918.

1,288,242, 4 Patented Dec. 17, 1918.

IN V5 TO? WILL/HM fl. S/PPEA WILLIAM H. SIPPEL, 0F INDIANAPOLIS, INDIANA.

SPARK-PLUG.

Specification of Letters Patent.

Patented Dec. 17, 19111 5.

Application filed May 6. 1918. Serial No. 232.853.

T 0 all whom it may concern:

Be it known that I, WILLIAM H. SIPPEL, a citizen of the United States, and a resident of Indianapolis, county of Marion, and State of Indiana, have invented a certain new and useful Spark-Plug; and I do hereby declare that the following is a full, clear,

This object is accomplished by providing a plurality or number of spark gaps in series so that if one gap should be filled with carbon, there will be one or more other gaps where sparking would still take place. If there are three gaps in series, the spark plug would operate until all three of the gaps are filled with carbon, and there 1s usually three times the probability of three gaps not being closed by carbon than one.

Another feature of the invention consists of the particular form and arrangement of the electrodes for obtaining a considerable number of spark gaps and preventing short circuiting.

Another feature of the invention is that by providing a plurality or series of spark gaps, should one of the gaps become clogged with carbon or other obstruction the heat within the combustion chamber will soon burn the carbon or the like from the clogged gap. as the firing operation is carried on by the unclogged gaps.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

In the drawings, Figure 1 is an elevation of said spark plug. Fig. 2 is a central longitudinal section thereof on line 2-2 of Fig. 1. Fig. 3 is a perspective view of the lower end of the spark plug on a larger scale and parts being broken away. Fig. 4 is a bottom view of the spark plug on a greatly enlarged scale. Fig. 5 is an elevation of the lower end of the porcelain indicator with intermediate electrodes thereon, the major portion of the insulation being broken away.

Fig. 6 is a transverse section on line 6-43 of Fig. 5. Fig. 7 is a bottom view of a modified form of spark plug. 1

The major portion of the spark plug may be constructed in the usual form. As shown herein the usual porcelain insulator 10 is provided with an annular shoulder 11, located in the outer enlarged bore of the nut 12, and held in place by the follower 13. The conductor rod 14 is located in the center of the insulator and has a screw cap 15 thereon for electrically connecting one terminal of the sparking circuit with the spark plug. At the lower end of the rod 11 there is a positive electrode 16 which may be made in the usual or any other form. In the form shown in the first six figures the negative electrode 18 is secured to the nut 12, and therefore grounded as usual. These two electrodes 16 and 18 are not close enough to each other for passage of current directly from one to the other or for arcs or sparks to form between them, as appears in Figs. 3 and 4.

The positive electrode 16 which is centrally located and has its outer end bent radially in a direction away from the negative electrode 18 and the negative electrode has its end bent toward the positive electrode but not close enough to form an arc.

On each side of the positive and negative electrodes there is a pair of intermediate electrodes20 and 21. The stem of the intermediate electrode 20 is close enough to the positive electrode 16 to cause an are between them. Likewise the intermediate electrode 21 is close enough to the negative electrode 18 to cause an are between them. The ends of the intermediate electrodes 20 and 21 are bent so as to extend toward each other and leave a spark gap between them. These ends are preferably curved concentric with the stem of the positive electrode, as shown in Fig. 4, so that the arms or bent portions thereof will be remote from the electrodes 16 and 18. The intermediate electrodes on the two sides of the 'main electrodes are similarly constructed and the spark gaps are made identical in length.

The intermediate electrodes may be mounted as in Figs. 2, 5 and 6. An annular groove 25 in the porcelain insulator is located near its inner end as seen in Fig. 5, and there are longitudinal grooves 26 in the surface of the insulator connecting the groove 25 with the inner end of the insulator. The electrodes lie in these grooves 26 and their outer ends are bent so as to lie in the groove 25 and when they are all in place they are held there by a sleeve 27 as seen in Fig. 2, which surrounds the inner portion of the insulator and the intermediate electrodes.

The spark plug shown in the first six fi ures operates as follows. The current comes in through the electrode 16 and jumps from the bent end thereof to the intermediate electrodes 20 and from them to the intermediate electrodes 21 and from them to the bent end of the negative electrode 18. With this arrangement it is obvious that the plug will continue to spark until all of the spark gaps on one side have been filled with carbon. If one spark gap or even four of them, two on each side, fills with car bon, the plug will continue to operate. For this reason it will require much inore time for the carbon to disable the spark plug than when there is only one spark gap.

In the form shown in the first six figures there are two semicircular series of spark gaps provided, which is a very convenient and compact arrangement and will accomplish the same result as if there were merely one series of six spark gaps, for if all the spark gaps arranged as shown in Fig. 4, be a come filled, except one on each side, the spark plug will operate just the same, and will not cease to operate until all three of the spark gaps on one side are closed.

The invention is not limited to the double series of spark gaps, for the electrodes can be arranged so as to provide for six spark gaps in one series as shown in the modified form in Fig. 7, where the negative electrode is placed next to the positive electrode but so far away as not to short circuit.

Not only will spark. plugs arranged as shown herein operate relatively a very long time before being disabled with carbon, but there are other advantages resulting from this arrangement. Since there are so many spark gaps to be relied upon, they can be made smaller than when there is only one spark gap and yet all six of them be less liable to fill with carbon than one wider spark gap. This reduction in size of thegaps enables a. relatively weak current to cause the device to operate.

Also six simultaneous sparks or any'relatively large number of sparks will increase the fatness of the spark and, therefore, be more efiective in causing ignition. It will likewise be seen that should one or two of the spark gaps of each series, theybeing are ranged in multiple, become filled with soot, oil or other obstructions, so as to prevent a spark at these points. the'hot explosions caused by the sparks from the remaining 1 ,aeaaea gaps, will soon clean the fouled gap or gaps. Under these conditions and owing to the fact that each gap fires independently of the others, an absolutely continuous fire or spark will result as long as current is supplied to the plug.

The invention claimed is 1. A spark plug having an insulator, a positive electrode extending through said insulator with its inner end bent, a negative electrode with its inner end bent, one or more intermediate electrodes located beside the bent ends of said other electrodes and having bent ends forming equal spark gaps and so that the current will pass through the electrodes in series and a sleeve slidable on the insulator for securing the intermediate electrodes to the insulator.

2. A spark plug having an insulator section, a nut cooperating therewith, an electrode with its stem extending centrally through said insulator and its inner ends bent radially outward, another electrode attached to said nut with its stem eccentrically located to said insulator and its inner end bent towardthe first electrode, one of said electrodes being positive and the other negative, intermediate electrodes located beside the other electrodes with their stems nearer the stem of the central electrode than they are to the stem of said second electrode, and with their inner ends bent to form a series of substantially equal spark gaps between all of said electrodes and extending in circular formation, and an insulating sleeve slidable.on the insulator section for removably attaching the intermediate electrodes to the insulator.

3. A spark plug having a positive electrode with its stem centrally located and its inner end bent radially outward, a negative electrode with its stem eccentrically located and its inner end bent toward the first electrode, intermediate electrodes located beside the other 'elcctrodes with their, stems nearer the stem of the positive electrode than they are to the stem of the negative electrode, and with their inner ends bent concentrically of the stem of the positive electrode and so as to form a series of equal spark gaps between all of said electrodes, the bent ends of said intermediate electrodes extending a distan'ce beyond the bent ends of the positive and negative electrodes, and, an

insulated sleeve-slidable on the insulator section for removably attaching the intermediate electrodes to the insulator.

fl. A spark plug comprising a'one piece insulator having an annular groove adjacent its inner end. and longitudinal grooves in the surface thereof extending from said inner end to said annular groove, a nut coop- 'erating with the insulator, a positive and negative electrode carried by said insulator and nut, respectively, a plurality of intermediate electrodes adapted to lie in the longitudinal grooves and having their upper ends bent to lie in the annular groovesand means slidable on said insulator for removably securing the intermediate electrodes to the insulator.

A spark plug comprising an insulator having an annular roove adjacent its in.-

ner end, and longitudinal grooves in the surface thereof, a nut cooperating With the insulator, a positive and negative electrode carried by said insulator and nut, respectively, a plurality of intermediate electrodes adapted to lie in thelongitudinal grooves and havingtheir upper ends bent to lie in the annular groove, and a sleeve slidingly mounted on the insulator for holding said intermediate electrodes in engagement With the insulator.

In witness whereof, I have hereunto af- I fixed my signature.

WILLIAM H. SIPPEL. 

